Research And Application On Optimized Control Method Against The Fermentation Process

The microbial fermentation involves the pharmaceutical, food and other industries, and is closely related to economic development and people's everyday life. High cost and energy consumption are the characteristics of microbial fermentation. Therefore, in order to improve the fermentation unit and reduce production cost, it has become an important issue to realize optimal control of fermentation process.This paper studies optimize fermentation process control based on the mechanism model fermentation process, In the optimization process, Capping phenomenon does not occur if we meet the conditions of cell growth and the synthesis conditions of the product.In this paper, a hybrid algorithm is proposed—Sequential Quadratic Programming Based on Simulated Annealing,which is based on differential properties. Main research results are as follows:1) Through the research advantages and disadvantages of certainty algorithm and random algorithm, this paper proposes a hybrid algorithm, In the early stage it adopts SQP for local optimization, then use SA for global search, jumping out of the local minima. In such way the probability acquiring global extreme value point increase greatly, and accelerating the convergence speed.2) In the mechanism model of fermentation, state variables can be regarded as the implicit function of control variables, this function is often difficult to write the analytical expression, constraints can not directly calculate the gradient. This paper uses control vector parameter (CVP) method to discrete the original optimal control problem, thus the optimal control problem is transformed into solving nonlinear programming problem.3) A set of software for optimization of the fermentation process has been designed by VC++ 6.0 in Windows system. fermentation process is controlled across the changing curve of control vector,which is obtained through the proposed optimal control algorithm.